1. Technical Field
The present invention relates to a pretreatment agent for ink jet textile printing that can provide printed matters on fabric with high color-developing properties and less bleeding, and also relates to an ink jet textile printing process using the pretreatment agent.
2. Related Art
Ink jet textile printing has advantages in that labor hours for printing plates, such as producing, storing, and washing of the plates, are not necessary, unlike known textile printing, and that images excellent in gradient can be formed on-demand. The method of printing on fabric by an ink jet system is suitable for producing high-mix, low-volume products, can reduce loads due to liquid waste disposal, and enables a reduction in delivery time, and is, in these respects, superior to existing printing processes, such as screen textile printing.
In printing on fabric by the ink jet system, an ink having a low viscosity of about 10 mPa·s or less is usually used in terms of discharging property, or the fabric is generally subjected to specific pretreatment from the viewpoint of preventing bleeding after printing, since the fabric is insufficient in function of promptly absorbing ink and fixing it. For example, JP-B-63-31594 discloses fabric for ink jet dyeing, wherein the fabric is pretreated with a certain amount of a pretreatment agent composed of a water-soluble polymer substantially not dyeing the dye that dyes the fabric and a water-soluble salt or water-insoluble inorganic fine particles to provide a sharp and clear image.
In addition, for example, JP-B-4-35351 discloses an ink jet textile printing process using a high-temperature reactive dye ink, wherein a cellulose fiber structure is pretreated with an alkaline material, urea, and a nonionic or anionic, water-soluble polymer to enable dyeing deep colors clearly and without bleeding.
The purposes of any of the above-described methods are prevention of bleeding of images and acquisition of clear and high-concentration dyed matters, but the color density and the clearness achieved by these methods are still lower than those of dyed matters obtained by existing screen textile printing. Furthermore, in these pretreatment, processes, in usual, a pretreatment agent is applied to fabric by means of, for example, dipping or coating. However, there are a tendency that bleeding is further increased with a recent increase in printing speed, and thereby a demand for further improvement in pretreatment prescription for preventing bleeding.
At the same time, in order to prevent bleeding in printing on fabric, various methods and technologies have been disclosed. For example, JP-A-60-81379 and JP-2003-55886 disclose methods preventing bleeding by utilizing interaction between components in ink and components applied to fabric by pretreatment. These methods are accompanied by an increase in steps, that is, specific treatment of fabric, and the ink needs to contain an additional component (e.g., gelling adhesive), which causes a problem to deteriorate storage stability of the ink,
Furthermore, for example, JP-A-2002-19263 discloses a technology utilizing interaction between an ink and another liquid separately prepared. This method does not need pretreatment of fabric, but cannot be practically used because of insufficient effect of preventing bleeding and deterioration in storage stability of the ink. Therefore, there is a demand for development an ink jet textile printing process that can provide a printed matter having a high color-developing property and being very low in bleeding.